Beam Dynamics Challenges for the LHC and Injector Upgrades

The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) will rely on significantly higher bunch current and brightness to meet the future yearly integrated luminosity target. The implications are twofold. On one side, all the accelerators of the LHC injection chain will have to be upgraded to produce the desired beam parameters. For this purpose, the LHC Injectors Upgrade (LIU) program has been established to implement all the needed modifications for meeting the required beam specifications. These upgrades will lead to the lifting of the main intensity and brightness limitations in the injectors, linked to beam instabilities driven by impedance or electron cloud (e-cloud), and space charge. On the other side, the LHC will have to be able to swallow the new beam parameters. This will mainly require control of impedance driven instabilities and beam-beam effects, and e-cloud mitigation. In this paper, we will focus on proton beams by describing the identified performance limitations of the LHC and its injectors, as well as the actions envisioned to overcome them.